308 reloads won't chamber

[boostedtt91]

I keep having problems with my 308 reloads and im at the end of the rope as far as knowing what else the problem is. I keeping having reloads not chambering completely and the base of the bullet is marked up. I have this issue with a number of different types of brass, its all being full length sized, all in spec for length and fits into a headspace gauge.
I have 7 other calibers i reload using all RCBS dies and never had any issues before. When i bought the 308 dies, all they had at the time was Hornady dies so i decided to give them a try. Im not sure if its a problem with the die or something i am doing wrong. When i attempt to chamber a round in my AR10, the bolt won't completely close and then i have to pound the stock on the ground to get it back out cause its getting stuck that good. Help please!

[inpursuit]

Are you full length resizing the cases? Semi auto weapons most of the time need full length sizing.
My 2cents

Bill

[jwrowland77]

So you're going from bolt to AR? I don't know if they make a small base die for 308, but I can't see why they wouldn't.

Is the die hitting the shell holder when you lower the press handle all the way?

[USMC 77-81]

I had the same issue with my M1A. Screw the sizing die into the press 1/8 turn at a time, run a case in to full stroke. Plunk test the case in the chamber. When it plunks release the BCG under full spring force. If it goes fully in to battery try extraction with the charging handle as usual, if all goes well at that point you should be good to go. Proceed using standard powder charging, bullet seating and COL till you find the load your rifle likes. Also, in the future keep your AR cases separate so they are fire formed to the AR chamber.

[precision_shooter]

Agree with above. Die not adjusted properly causing the shoulder to not get resized correctly or the base of case to not get fully sized. Do as mentioned above, should fix your problem.

[boostedtt91]

yes as stated above they are all being full length sized. No the brass is all from a semi auto. I just purchased a 308 remington 700 the other day so i will now have a bolt 308 as well to reload for which i did plan to separate the brass for, but i haven't used any brass from a bolt yet.

As of right now the die touches the shell holder, i haven't turned down anymore yet since Hornady tells you to just touch the shell where all my RCBS tells you to turn it down past where the shell touches so i will give that a try. So once i size the brass, drop it into the chamber to see if it clunks and then drop the bolt and see if it extracts ok?

[SWThomas]

When you say headspace gauge, do you mean case gauge? If so, my advice would be to ditch the case gauge and get an actual headspace gauge. Case gauges are good for spot checking pistol cartridges, but are pretty worthless for loading rifle. I like the Sinclair comparator body with a bump gauge insert for the caliber I'm loading. That way you can measure from the shoulder to the base of a fired cartridge and then set your sizing die to bump the shoulder back. The recommended bump for auto loaders is 0.003-0.005.

I never liked the whole "screw the die in until it touches the plate and then screw it in another --- turn" thing. That'll get you some reliable rounds but it's oversizing the shoulder more than needed. You'll get more life out of your brass by just bumping the shoulder back the amount listed above, and it will be just as reliable.

[boostedtt91]

yeah the Lyman "headspace" gauges thats basically a piece of metal that has the caliber chamber cut out and you drop the sized brass into it and make sure it sits flush in the gauge

[USMC 77-81]

I don't have any Hornady dies so I can't speak of them, you could call Hornady CS and ask as to proper set up. RCBS states specifically to adjust the die down until it touches the shell holder then 1/8 - 1/4 futher until you feel the ram cam over, if you're not doing that then you are not applying sufficient pressure to (re) form the case.

[Rifletom]

I didn't see this, but, you are trimming?

[dmazur]

This has come up quite frequently -

1/8 - 1/4 futher

At 14tpi, 1/8 turn is approximately 0.009".

Typical difference between min and max cartridge "head to datum" (aka cartridge headspace sometimes) is on the order of 0.006".

So if you manage to come up against the shoulder at 1/8 turn further, with all the flex taken out of the press, that extra 1/8 turn to get to 1/4 turn can create instant induced excess headspace (if the die permits it - mfgrs usually try to make this very difficult to do unintentionally.)

Just like your rifle had excess headspace. And it is an unsafe condition to deliberately set up.

There are a variety of techniques in use, including using the chamber of a bolt-action rifle as a gauge and increasing the amount of resizing in very small amounts until you get a no bolt resistance fit. But these are not suitable for a gas gun like the AR-10.

IMO, you need some kind of measuring system. Once you have determined, through trial and error if necessary with dummy rounds, what amount of resizing provides fail-safe chambering, you can measure that case and use that measurement to set up your die to create the same thing in later sessions.

Of course, there are fun details like brass spring-back changing with successive reloadings. But if you segregate your brass by number of firings, that will help with uniformity.

And gas guns are so hard on brass, most reloaders don't expect more than 5 or 6 firings from a case anyway...

[Jeff2131]

Take a straight razor blade and lay it across the length of the case from base to shoulder. Ill bet youll see something that will explain why your rounds wont chamber and the bolt locks and gets stuck. ;-)

[boostedtt91]

im worried im gonna break something if they keep getting stuck till i get the sizing figured out since i have to bang the crap out of the gun to get it to extract. So should i just try turning the die down alittle more and see if that makes it better?

[SWThomas]

I say to stop until you have the proper tools. You shouldn't rush it.

[skizzums]

could you show a pic of the bullet after being fudged up when it gets stuck?

[nemesiss45]

are you crimping? do the bullets have a cannelure?

back in the day when my dad was teaching me to reload, we made a batch of .223 were either over crimped or we tried to crimp without a cannelure (been so long I cant remember which)... anyway, the crimping slightly ballooned the shoulder and we had to fight every one of them into his AR

but if you took a close look at those cases, it was plain to see with the naked eye, so maybe you're having another problem

[49willys]

A good clear picture of a fired case might help.especially if there are any scratches or other marks in the case.

[Salmoneye]

Could indeed be over-crimp...Could also be bullet profile hitting the rifling...

Need pics...

[cw308]

You seem to be doing everything right as per your post, can you chamber just the case.

[USMC 77-81]

Hey Boost, go to '1911 forum' (sorry I don't know how to supply a link) and click on reloading bench > .223/5.56, scroll down a few and read post by Nick, it is very good.

[boostedtt91]

here is a pic of the one that got stuck

[jwrowland77]

Almost looks like it getting stuck in the lands.

[boostedtt91]

no its not being crimped

[49willys]

Is that a dent i see in the bottom of the shoulder?how about the bullet,in the picture it looks like there is a bad scratch or somethin.

[TATER]

Flip the round and show me the other end.